1. Field of the Invention
The invention relates to a device for measuring the fluorescence of a medium having at least one radiation source, at least one emission-receiving element and at least one optical imaging element, wherein the radiation source and the emission-receiving element are arranged on the sensor side of the optical imaging element and wherein the radiation source, the imaging element and the emission-receiving element are aligned and designed in respect to one another so that the medium present on the medium side of the imaging element can be illuminated by radiation from the radiation source and the emission intensity of the medium radiation emitted by the medium based on fluorescence can be detected with the emission-receiving element, wherein at least one scattering-receiving element is arranged and designed on the sensor side of the optical imaging element so that the scattering intensity of the medium radiation scattered by the medium in the range of the absorption of the radiation of the radiation source caused by the fluorescence of interest can be detected with the scattering-receiving element.
2. Description of Related Art
Measuring devices of this type have been known for a long time and are used, for example, in the fields of chemical analysis and in environmental and quality control. Such devices use the fluorescence of particles of the medium—fluorophores—i.e., the short-term emission of light from fluorphores caused by suitable spectral electromagnetic excitation. Radiant energy is absorbed by the fluorophores and—partially—re-released by emission of light based on fluorescence, wherein the emitted light has a characteristic spectrum, i.e., radiant energy is only emitted at certain frequencies. The emission intensities of the medium radiation emitted based on fluorescence detected by the emission-receiving device, thus allows, for example, a conclusion about the concentration of the fluorescent particles of interest within the medium.
The extent of the emission intensity detected by the emission-receiving element, i.e., the medium radiation emitted from the medium based on fluorescence, depends—as in many real technical measuring devices—on the constructive design of the measuring device, for example on the arrangement of the emission-receiving element, the medium and the radiation source in relation to one another, so that it is to be taken into account that the part of the medium radiation emitted based on fluorescence, which is detected by the emission-receiving element, allows a reliable conclusion about the entire emission intensity. Naturally, such a measurement is afflicted with some uncertainty.